Work-holding device



WORK-HOLDING DEVICE Filed March 8, 1943 21 El El -H96. z3clz 9 uuuux h 7 22 b 6 +11 9 H 4 e HARRY D M ANNING I INVENTOR Patented Apr. 3, 1.945

UNITED STATES PATENT OFFICE 2,372,727 WORK- HOLDING DEVICE Harry D'. Manning, Kalamazoo, Mich. Application March 8, 1943, Serial No. 478,466 3 Claims. (01. 144-305) This invention relates to clamps and clamping devices andparticularly to the type thereof providing means effecting quick manipulation combined with positive action.

The principal object of this invention is to provide a clamp of the type mentionedwhich may be moved into and out of clamping position in a minimum time and with minimum effort.

A major object of this invention is to provide a clamp of the type described in which the clamping members when in engaging position are positively engaged with no opportunity for slipping.

A further object of this invention is to provide a clamp of the type described which is sturdy and strong and is free of complex and/or delicate Darts.

A further object of this invention is to provide a clamp of the type described whose parts are relatively simple in shape and can be rapidly fabricated by the use of ordinary machine tools.

A further object of this invention is to provide a clamp of the type described which can be manufactured rapidly and cheaplyyet be sturdy,

- strong, rapid in use, and positive.

All of these desirable ends I have secured by,

the clamp described hereinafter and illustrated by the accompanying drawing.

Referring now to the drawing:

Figure- 1 shows a side View of the portion of an ordinary C-clamp upon which the adjustable holding means is mounted.

Figure 2 shows a view partially in section taken at line II-II of Figure .1.

Figure 3 is a partial section taken on line IIIIII of Figure 2, and in an enlarged scale.

Figure 4 is a plan view of one of the internal members.

Figure 5 is a plan view of another of the internal members. I

Figure 6 is a partial section taken at line V'IVI of Figure 3. I

The use of C-clamps being very old, there has long been a desire and need for a satisfactory means for making them quick and easy to operate without sacrificing positiveness in holding. The conventional screw type is slow but has hitherto been unexcelled in its positive holding. The presently known quick-acting types are legion in number but are either prohibitively expensive to manufacture, impractical to operate, or are insufficiently reliable in holding to be trustworthy. Many types havebeen suggested and many types are now in use, but none to myiknowledge -adequately meet the above requirements.

The hereinafter disclosed invention does meet these requirements and is therefore considered both new and useful. Its principle is illustrated by assuming application to a C-clamp, but it can readily be applied to any other device, such as a vise, wherein adjustable holding means are desired. Such applications are within the scope of this disclosure and the hereinafter appended claims, excepting only as such claims may be otherwise expressly limited.

In Figure 1 the C portion of the clamp is indicated at l and it has an enlarged portion at I-a for the reception of the movableclamping rod or shank 3. This shank is manipulated by handle I6, which is of any conventional kind and aflixed in any conventional manner; the work engaging end, or foot, I! may be of any conventional type to bear in the usual manner against a suitable conventional gripping surface at the other extremity of the G. Since the general construction of a C-clamp is well known, no further reference need be made to it. My invention concerns the means for accommodating the shank 3 within portion I-a of the C, moving it into gripping position, tightening it therein, loosening it again, and removirg it from gripping position, and hence only the parts of the clamp related to such functions need be, and will be, detailed.

Enlarged portion l-a, has an opening therethrough of size suitable to accommodate sleeve 2. Said opening is threaded internally and sleeve 2 is threaded externally at 2--a for mutual interaction so that rotation of sleeve 2 will move it upwardly or downwardly (as sam is illustrated in Figure 1) according tothe direction of rotation. Shank 3 is square in cross-section but regularly spaced portions I!) are machined to become circular in cross-section, as bestshown by the sectioned portion of Figure 2. In this manner a series of teeth II are formed on what then becomes a round shank, but a section through any' of the teeth is square. It will be noted that the teeth are oppositely placed and do not advance in the manner of a screw thread; they are formed by a simple and direct machining operation which promotes inexpensive construction. Returning now to the construction of sleeve 2, with particular referenc to Figure 3, it will be seen that an internal axial opening extends throughout its length. One or more channels I8 are placed, as by broaching, along the interior of Y nessof teeth and, spaces ll members, or plates, 1 and 8. These are placed alternatingly within said sleevewith their lugs 9 in channels I8 holding them from turning with respect to sleeve 2; the number of such plates will depend upon the strength desired to be available to the clamp. As the desired strength is increased, the number of necessary plates will increase and will in turn require a corresponding increase in the length of sleeve 2. A sleeve or collet 25 may fill the remaining space within sleeve 2, excepting onlythe ends, which are occupied by rings 4 and 4a threadedly secured in place and holding all of th foregoing within said sleeve. Rings 4 and 4a have interior diameters less than the external diameter of=-co'llet'25-:and plates 1 and 8 but great enough .to-permitshank 3 to rotate freely therewithin.

Plates i and 8 each have-.a central: opening and these plates differ from each other only in the shape of their respective central openings. The openingst in plates 8.are square and of size slightly greater than .1thesize .ofeshank 3, so that shanlnli, when turnedlinto register therewith may. pass freely, :thereth-rough .but; will :fit

. closely'therewith v(Figure-2). Withayshank of inch-square measurement,- ppening 5 may-abe made approximately /32 inch square.

JPlates l. are. 1 providedwith :central opening 5 of the generally wideorossyshape shown in Fig- -ure J 4. Portions ":22 of -.said ;.opening rare .arcs

centered in theaxis ofrsha'nk-S when same-is in position within said plates as shownxin :E-igure 6..

The radius of said .arcs iszsuiiicient torlpermit teeth H to cclearthese .portionslof plates 1 as shown in-Figure 6. .Arcs. :22.xterminate:at::in

- wardly extending surfaces 23-and1 23aiwhich: meet =to define extending portions 24. :Su-rfaces =23 .and 23a. may be .oiany :shape efiectivegto'intercept teeth ll ofshank 3.an'd limitrotationtherenot ineither dire'ction'to thearcuate distance between said surfaces-:23: and 23a. yConveniently, and as shown, surfaces: 23and-.23armay be-shaped to lie flat againstxthe respectively. contacting surfaces 50f :teeth. I l when shank 3-hasrby rota- .tionin either direction reached jthe .limitdedined by said-"surfacesS-H,and;.;23a. "One of-; these positions v:is illustrated in Figure '6.

.In assembling theqsleeveunit with-ring ta and vcolletdfiin place, plates 1 .andi-B in theidesired number are .sliiiipediinto said .sleeve; from end t with their-lugs ll lyingin channels 48 ,and the sleeve is filled slightly more than to theinner surface of ring .4. [Ring 4,.is .thenthreadediinto place :and .tightenedi downlonto. plates 1. and 8 to hold them'firmlyagainstcollet :25. asaid' rings 4 and Act maybe manipulated in'any, convenient manner, as by -providing.:openings therein to receive a small spanner :wrench. .=Whenever ,desirable, it is obviously .easy to remove-retaining rings 5 or iaeand .all of the,.parts ;contained between them for, replacement 3,01" gcleaning.

Since lugs 9 appear on both series of plates, the .proper '.positioning of the 'two .-series with respe etto each, other is: easy and positive. When so installed, the .respeotiveopenings will lies-with respect to each otheras shown in-Figure 6, wherein the solid lines represent {the sectionindicated and the dotted linessuperimposed thereon-represent the outline of the, centralopening of plates 8.

Although normally plates 'l-and fi-lwillxbe of thickness equahto each othereandlto the :thickand :l 0,:it is obviously possible .to secureeasier punching :eby making each of either, plates: 1: or 8,. or .-bot h, of thinner material and piling the units to secure the arrangement shown. For example, plates 1 and 8 may be made of material of the thickness of teeth or spaces 10, in which case three plates of shape 1 will be used, then three plates of shape 8 will be used, then three plates of shape I, and so on until the required number is obtained Collet 25 is a useful but not indispensable addition to the clamp. Externally it is round and .of, diameter to enter, easily, into the internal opening, of sleeve 2. Internally said collet has a square opening fitting slidably but closely around the square section of shank 3 represented by teeth II (for example, /64 inch clearance). .Alight spring 21 is fastened at one end in any convenient manner to collet 25, as by insertion of said one end at 20 into a small opening in Jthe.=,:side .0f.isaid collet 25; it is then wrapped several ,times around said collet to place it under tension and its other end inserted into an -openingin ring-icu; asindicated; at 21. In this -.W, y..;there :is always .a force .urging rotation izplaced upon shank 3. It, may, however, be omitted and the sleeve:.either; shortened. or en- .tirely: filled with-plates 1 and, 8.

The operation of this. Speed. clamp is probably obvious iirom .therdescription given, thus ,f-ar, but for the .purpose;ottompleteness -itwillloe'outdined. 7

;The .'clamp,iis assembledgwith-sleeve 2 holding ring 14,; plates 'lwandrfi, colletz25, and. ring-4a. QShank'B; extendsthrough the .openings within ,ring14,.; plates lwandzfi, collet;-l25,-l.and ring 4a,

1 and: :the entire1 assembly is threadedly accom- .::m0dated\by;,the frame of-clamp l, or-by the corresponding part of a vise or whatever other.delvice :is being used with "this quick-acting mecha- ;-nism. Shank 3 is-rotated.;to.,.bring theesquare out1ineof its teeth ll=into register with the corresponding outlineof openings Bin-plates 8. It ecan then lbedmanually, ,directiy, vand rapidly pmoved into such position :that the clamp,-or vise,

,-;lightly grips: the: objectv to {be lheld .by .it. vShank 3 s then dl'llstedsl htlyif necessary tobring teeth 1 i-. intoregister with. :platesland rotated. .Ii-sleeve 25.. isused .its, spring-2i will-assist in this rotation of'shankf-fi. lrBy'Hthis rotation teeth ii move clockwisee'as seen :in-Eigure-o toward thelimits;peImittd1VbyiuEfaGeS.23 0f".plat(-3S l and. so;.-doing .moves'out tofrregister with the square openings of-lplatest. .-;Shank:3 thus can a not :move back. away "from \thework; 0r;otherwise move longitudinallywith'respect :to sleeve 2. As shank B is :iurther turned clockwise, :as appearing in Figures -l and =6,- the-teeth llrwillbear against adjacent -surfaces +23 andl urgeplates l to move clockwise. This urging acts through --lugs 9 of saidrings 'i and causes sleevevE to turn clockwise by which it is advanced-upward as same appears-in -Figure 1, thus 'to tighten shank 3 against the work being'held. When -it-is desired to loosen" theclamp, it is necessary only to turnshank"fi-counter-clockwise to turn teeth 1 ii back into registerwithopenings i5 in-plates '8, .whereupon the shank 3-may be instantly ',.drawn backward as'desired.

, Particular attention is called to the fact that the above disclosed and described clamp, bevsides being rapid and positivehin' its operation, v,canbe fabricated throughout by simple machining processes, such, as.lathe work, andby cold,1s tamping. .lIts assembly is rapid and may be accuratelyeffiected by vunskilled workmen. Hence, the cost-.ofmanufacture of this clamp threaded sleeve accommodated therein; a se ries of contiguous plates of equal thickness within said sleeve perpendicular to the axis thereof, and a lug on each of said plates fitting into a channel in the interior of said sleeve and holding said plates against rotation with respect to said sleeve; means holding said group of plates against movement one way longitudinally of said sleeve and an externally threaded ring retained by internal threading within said sleeve holding said plates against movement the other way longitudinally of said sleeve; a square opening in alternate plates throughout the length of said group of plates and an opening in the remainder of said plates of the pattern of a wide cross having tapering limbs with arcuate ends; a square shank having cuts each of a width sufficient to accommodate one of the above-mentioned plates and spaced apart a distance equal to the thickness of the above-mentioned plates, said cuts defining a circular section providing oppositely spaced teeth on said shank which shank is located within said openings in said plates and extends axially through said sleeve; said openings in all of said plates being of size and alignment to provide a continuous channel of cross-sectional area suflicient to permit said shank in one rotative position to pass freely longitudinally therethrough and providing by the said cross-shaped openings in said second-named plates a series of recesses in the walls of said channels receiving the teeth of said shank in another rotative position thereof, and abutments Within said recesses limiting rotative movement of said shank with respect to said sleeve; manipulative means on one end of said shank and work engaging means on the other end of said shank.

2. In a quick-acting, work-holding device having a body part including fixed work-engaging means; a threaded opening within said body part; an externally threaded sleeve accommodated within said opening; two groups of contacting plates of equal thickness within said sleeve perpendicular to the axis thereof, the individual plates of one group alternating with the individual plates of the other group; means holding said plates against rotation with respect to said sleeve; means holding said plates against movement longitudinally in either direction with respect to said sleeve; a central opening of one angular shape in each plate of one group of plates; a central opening of a larger and different angular shape in each plate of the second group of plates; a shank member having'a crosssection geometrically similar to, and slightly,

date one of the above-mentioned plates and spaced apart a distance equal to the thickness of the above-mentioned plates; the portion of the shank between said cuts forming a series of equally spaced and oppositely positioned teeth; said openings in all of said plates being of size and alignment providing a continuous channel of sufficient cross-sectional area to permit said shank inone rotative position to pass freely longitudinally therethrough and providing by the openings in the second named group of plates a series of recesses in the walls of said channel for the reception and engagement of the teeth of said shank in another rotative position thereof, and abutments within said recesses limiting rotation of said shank relative to said sleeve; manipulative means and work-engaging means operatively associated with said shank.

3. In a quick-acting, work-holding device having a body part and fixed work-engaging means thereon, a sleeve threadedly accommodated Within a portion of said body part; a shank co-axial with, and partially rotatable, relative to said sleeve and having manipulative and work-engaging means operatively associated therewith; said shank having a series of oppositely positioned and equally spaced teeth each of a thickness equal to the spacing between the teeth, and means operative inone position for engaging said shank and said sleeve for unitary rotative movement and operative in another position for disengaging same; said last named means comprising: a group of plates within said sleeve held against both rotational and longitudinal movement with respect thereto; the thickness of each individual plate of the group being equal-to the spacing between the teeth on said shank; an angular central opening in each alternate plate of the entire group, said opening being similar in cross-section to the shank and adapted to slidably but nonrotatably accommodate said shank, an angular central opening in each of the remaining alternately arranged plates of the entire group which openings are of shape difierent from the openings in said first-mentioned alternate plates, and which openings are defined by a plurality of arcs to rotatably accommodate said shank; shoulders between the contiguous arcs projecting into the opening and forming stops to arrest the rotation of said shank; said openings in all of said plates being of size and alignment to provide a continuous channel of sufficient cross-sectional area Whereby said shank in one rotative position will pass freely axially therethrough, and by virtue of said openings and shoulders in the second named group of plates will in another rotative position of said shank cause said teeth to be engaged by said shoulders to lock said shank and sleeve for unitary rotative movement thereof.

HARRY D. MANNING. 

